Tank vent



May 10,1927. A 1,628,069

G. c. SCHMIDT ET AL TANK VENT Filed A132. 21. 1926 gmwnlfou Patented May 10, 1927.

UNITED STATES PATENT OFFICE.

GEORGE C. SCHMIDT AND FRANK G. D. MULLER, 0F HOUSTON, TEXAS.

TANK VENT.

Application filed August 21, 1926.

This invention relates to new and useful improvements in a tank vent.

()ne object of the invention is to provide a tank vent specially designed for use in connection with a vaportight tank, or reservoir containing evaporative fluids such as crude petroleum or its derivatives and whereby the pressure of vapors generated within the tank, or a partial vacuum within the tank produced by condensation or contraction of vapor within the tank, or withdrawal of liquid therefrom may be relieved.

Another object of the invention is to provide a tank vent of the character described in combination with a novel type of controlling valve.

The subject matter of this application constitutes a divisional application and has been divided out of our application for patent on a combination tank vent, flame arrester and automatic snuffer filed by us in the United States Patent Otlice on March 30, 1925, under Serial No. 19,385.

\Vith the above and other objects in view this invention has particular relation to certain novel features of construction, operation and arrangement of parts. an example of which is given in this specification and illustrated in the accompanying drawings, wherein Figure 1 shows a fragmentary vertical sectional view of the tank vent.

Figure 2 shows a side elevation, partly in section, of the valve cage employed, and

Figure 3 shows a plan view of said cage, partly in section, on the line 3-3 of Figure 2.

Referring now more particularly to the drawings, wherein like numerals of reference designate similar arts in each of the figures the numeral 1 esignates a tank or reservoir which, except as hereinafter stated, is tluidtight. This may be a crude oil tank or a tank or reservoir for containing any other evaporativc fluid. The rent, it is to be understood, may be used in connection with any type of tank or reservoir where it is desired to maintain a substantially equal pressure within and without the tank; or to prevent the bursting of the tank from excessive pressure within it, or the collapsing thereof by reason of the outside air pressure, or where it is desired to safely permit the escape of inflammable vapors from the tank.

Serial No. 130,579.

The numeral 2 designates a vent tube which leads from the tank, preferably from the top or upper part thereof.

Fastened to the outer end of this vent tube there is a valve casing 3 whose upper end is normally closed by the removable screw plug 4. Formed integrally with one side of the casing 3, there is a tubular neck 5 whose outer end is flared and integral with this neck there is an inwardly extending shell 6. of semi-circular contour in plan view. The top and bottom of this shell have concentric circular openings 7 and 8 to receive the annular valve seats 9 and 10. These seats are anchored in fixed relation by means of the vertical anchor bars 11, preferably six in number, which are spaced apart and whose upper ends are also attached to the ring 1:! which is seated within the screw plug 4, when said plug is screwed into place. The seats 9 and 10, bars 11 and the ring 12 form a valve cage consisting of a unitary structure which may be bodily removed and replaced when the cap 4 is removed from the casing 3. For this purpose opening 7 is of a diameter to permit the passage through it of the seat 10. When these parts are re DiOVQd access to the inside of the tank is permitted. for measuring the fluid therein, or for any other desired )urpose.

The upper sides 0 the valve seats are formed with annular knife edges and they taper or decline outwardly from said edges. Seated on the respective seats 9 and 10 are the disc-like "alves 13 and 14 which are confined against lateral displacement by the bars 11 of the valve cage. These valves normally seat on the knife edges of said seats and form vapor tight joints therewith and condensation collecting on said seats will run oil the declining sides thereof and thus prevent the collection. on said seats, of any substance which would tend to cause the valves to stick. or adhere to said seats.

The shell 6 is spaced from the walls of the casing 3 forming the air inlet pa sageway 15 in the vent tube 2.

With the tank wholly or partly filled with petroleum the vapors of the same will gradually create pressure in the tank until the pressure is sufiicient to lift the valve 14 from time to time to permit the escape of the vapor. The pressure required to lift said valve will depend on the weight of the valve.

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The vapor thus escaping will thus pass out to free air through the neck 5. In case petroleum is drawn oil from the tank, or in case of condensation or contraction of vapor in the tank a partial vacuum will be created in the tank and the outside air pressure will lift the valve 13 and admit air into the tank through the passageway 15 and thus either an excessive pressure in the tank or a par tial vacuum therein will be automatically relieved.

The cage may be assembled in any preferred manner preferably by welding some of the bars 11 to the seats and to the ring 12 to anchor them in fixed relation and then seating the valves on the seats and then welding the other bars 11 in place What we claim is An apparatus of the character described formed with a passageway, valve seats disposed one above the other therein, valves controlling said seats, a cage-like structure anchoring said seats in fixed relation, said structure also serving to retain the valves in operative relation with the seats, said cagelike structure being removable with the valves from said passageway as a unit, said apparatus being provided with an opening: through which said structure may be removed, and a closure for said opening.

In testimony whereof we have signed our names to this specification.

GEORGE C. SCHMIDT. FRANK G. D. MULLER. 

